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adds Java9 Objects.requiresNonNullElse
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+166
-50
lines changed

4 files changed

+166
-50
lines changed

‎sources/net.sf.j2s.java.core/src/java/util/Objects.java‎

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@@ -204,6 +204,44 @@ public static <T> T requireNonNull(T obj) {
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return obj;
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}
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/**
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* Returns the first argument if it is non-{@code null} and
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* otherwise returns the non-{@code null} second argument.
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*
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* @param obj an object
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* @param defaultObj a non-{@code null} object to return if the first argument
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* is {@code null}
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* @param <T> the type of the reference
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* @return the first argument if it is non-{@code null} and
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* otherwise the second argument if it is non-{@code null}
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* @throws NullPointerException if both {@code obj} is null and
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* {@code defaultObj} is {@code null}
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* @since 9
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*/
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public static <T> T requireNonNullElse(T obj, T defaultObj) {
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return (obj != null) ? obj : requireNonNull(defaultObj, "defaultObj");
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}
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/**
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* Returns the first argument if it is non-{@code null} and otherwise
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* returns the non-{@code null} value of {@code supplier.get()}.
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*
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* @param obj an object
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* @param supplier of a non-{@code null} object to return if the first argument
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* is {@code null}
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* @param <T> the type of the first argument and return type
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* @return the first argument if it is non-{@code null} and otherwise
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* the value from {@code supplier.get()} if it is non-{@code null}
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* @throws NullPointerException if both {@code obj} is null and
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* either the {@code supplier} is {@code null} or
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* the {@code supplier.get()} value is {@code null}
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* @since 9
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*/
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public static <T> T requireNonNullElseGet(T obj, Supplier<? extends T> supplier) {
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return (obj != null) ? obj
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: requireNonNull(requireNonNull(supplier, "supplier").get(), "supplier.get()");
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}
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/**
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* Checks that the specified object reference is not {@code null} and
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* throws a customized {@link NullPointerException} if it is. This method

‎sources/net.sf.j2s.java.core/src/test/Test_J8_lambdafinal.java‎

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@@ -0,0 +1,52 @@
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package test;
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import java.awt.event.ActionEvent;
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import java.awt.event.ActionListener;
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import java.beans.PropertyChangeEvent;
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import java.beans.PropertyChangeListener;
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import java.util.ArrayList;
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import java.util.Arrays;
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import java.util.Comparator;
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import java.util.Date;
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import java.util.List;
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import java.util.function.BiPredicate;
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import java.util.function.Consumer;
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import java.util.function.Function;
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import java.util.function.Predicate;
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import java.util.function.ToIntFunction;
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import java.util.stream.DoubleStream;
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import java.util.stream.IntStream;
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import java.util.stream.Stream;
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import javax.swing.JButton;
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import javax.swing.SwingUtilities;
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import javax.swing.Timer;
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import test.baeldung.doublecolon.Computer;
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import test.baeldung.doublecolon.MacbookPro;
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public class Test_J8_lambdafinal extends Test_ {
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public static void main(String args[]) {
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testFinal();
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}
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private static void testFinal() {
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Runnable r = () -> {
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for (String s : new String[] { "a", "b" }) {
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Runnable r1 = () -> {
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for (int i : new int[] { 0, 1, 2 }) {
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System.out.println(i + " " + s);
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}
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};
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r1.run();
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}
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};
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r.run();
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}
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}

‎sources/net.sf.j2s.java.core/src/test/Test_Java8.java‎

Lines changed: 52 additions & 50 deletions
Original file line numberDiff line numberDiff line change
@@ -221,6 +221,58 @@ public void actionPerformed(ActionEvent e) {
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});
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}
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private static void checkData(Object data) {
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double[] datae = data instanceof String[] ? Stream.of((String[]) data).mapToDouble(Double::parseDouble).toArray() :
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IntStream.of((int[]) data).mapToDouble(i ->i).toArray();
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System.out.println(Arrays.toString(datae));
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}
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public DoubleStream values() {
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return IntStream.range(0, 4)
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.mapToDouble(this::get);
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}
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public double get(int row) {
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return row;
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}
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private static void testToIntFunction(TestFunc tf, Function<TestFunc, Integer> f) {
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int val = f.apply(tf);
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System.out.println("testToIntFunction =" + val);
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}
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private static void testToIntFunction(Object tf) {
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System.out.println("testToIntFunction = " + tf);
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}
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private static void testFunction(String function, int i) {
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// Function
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int[][][] a;
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Function<Integer, int[][][]> ifi = new Function<Integer, int[][][]>() {
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@Override
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public int[][][] apply(Integer t) {
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System.out.println(function);
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return new int[t.intValue()][][];
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}
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};
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a = ifi.apply(i);
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System.out.println("a length is " + a.length);
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}
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@Override
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public void propertyChange(PropertyChangeEvent evt) {
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// checking here that this is not qualified
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}
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public static void main(String[] args) {
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Test_Java8 t8b = new Test_Java8();
@@ -415,55 +467,5 @@ public void run() {
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System.out.println("Test_Java8 OK");
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}
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private static void checkData(Object data) {
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double[] datae = data instanceof String[] ? Stream.of((String[]) data).mapToDouble(Double::parseDouble).toArray() :
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IntStream.of((int[]) data).mapToDouble(i ->i).toArray();
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System.out.println(Arrays.toString(datae));
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}
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public DoubleStream values() {
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return IntStream.range(0, 4)
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.mapToDouble(this::get);
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}
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public double get(int row) {
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return row;
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}
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private static void testToIntFunction(TestFunc tf, Function<TestFunc, Integer> f) {
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int val = f.apply(tf);
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System.out.println("testToIntFunction =" + val);
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}
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private static void testToIntFunction(Object tf) {
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System.out.println("testToIntFunction = " + tf);
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}
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private static void testFunction(String function, int i) {
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// Function
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int[][][] a;
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Function<Integer, int[][][]> ifi = new Function<Integer, int[][][]>() {
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@Override
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public int[][][] apply(Integer t) {
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System.out.println(function);
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return new int[t.intValue()][][];
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}
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};
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a = ifi.apply(i);
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System.out.println("a length is " + a.length);
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}
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@Override
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public void propertyChange(PropertyChangeEvent evt) {
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// checking here that this is not qualified
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}
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}

‎sources/net.sf.j2s.java.core/src/test/Test_Objects.java‎

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@@ -0,0 +1,24 @@
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package test;
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import java.util.Objects;
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class Test_Objects extends Test_ {
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@SuppressWarnings("unused")
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public static void main(String[] args) {
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Object x = "";
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Objects.requireNonNull(x);
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if (/** @j2sNative true || */
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false) {
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x = "ok";
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x = Objects.requireNonNullElse(x, "testing");
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assert (x == "ok");
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x = null;
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x = Objects.requireNonNullElse(x, "testing");
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assert (x == "testing");
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}
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System.out.println("Test_Objects OK");
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}
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}

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